Akshay

What was done to get 230hps from 205hps from an 1991 LB9 engine?

Akshay

TunedPort 335

The 205hp one had what we call the "peanut cam". It was a very small cam that came in the automatic 305 TPI's.

The 230hp one had a larger cam and came in 5 speeds only. I beleive the cam is the same as what the L98's had.

SHO350

Dual cats. According to GM, it provided a 12.5%(which comes out to about 25 hp) power boost over the standard single cat system.

avro206

I'll back that up--cam was the same for 91-92.
Dual cats and probably smaller pipes.

Curiously the redline in an auto car stayed at 5000rpm

Ed Maher

The first poster is wrong. All SD 305s have the same cam. This has been proven by inspection (i.e. cams measured in engine, engines dissassembled and cam #s checked) as well as in official GM service parts literature, as well as by inference through performance and how well a 205hp LB9 reacts to mods compared to the MAF peanut cam cars.

The only difference between 90-92 205hp vs. 230hp LB9s was the exhaust only. The 230hp cars came with bigger exhaust manifolds and dual cats compare to TBI manifolds and a single 2.25" cat for the 205hp version.

I picked up 3 tenths and 2.5 mph just from switching from my stock exhaust to L98 manifolds and dual cats, and that was still with 2.73s. So there's an application of the idea that the exhaust is 25hp.

TunedPort 335

Ooops sorry about that guys. I'm used to the 85-90 cars!

Doh

87WS6

iTrader: (1)

I've got the peanut cam I think. As I have always stated before my car runs abit stronger than a 305 car usually runs. I have no time slips to prove that. I've occasionally raced other cars that I shouldn't have been able to beat quite so easily. And come out on top.

I would ditch that peanut cam but I consider it a waste of time and money simply because I am going to skip that and build another engine. 383 most likely.

jfreeman74

The LB9 in '85 I believe was best of the "305" engines with an automatic transmission. It did not have the peanut cam in it. The cam was changed in '86. In 87 they put the good cam back into the LB9 5speed and the L98 engines. So when you see people talking bad about 305's, it's probably not an '85.

Kevin91Z

iTrader: (1)

How can you say you have a peanut cam but then also say your car runs fast and beats other cars that it shouldnt?? That seems strange to me.

avro206

maybe someone swapped it out and he doesn't know...?

f-crazy

iTrader: (-1)

as ed said all sd cars got the l98 cam..


freeman...id race any 85 with my 91 t-5...
of course i blew the lb9 up lol...

jfreeman74

Yeah, and I would race a Viper too, but that doens't mean that I would win.